INTRODUCTION Definitive testing of the value of novel therapeutics and diagnostics in large randomized trials requires the prior execution of "early phase" trials that provide the information needed to design pivotal studies. Phase 1 trials are directed at determining doses of drug that are appropriate for subsequent trials and the pattern of adverse events produced. Feasibility and pilot trials are conducted to obtain preliminary information on the tolerability of particular drug combinations, the ability to measure effects on drug targets, or to assess whether a particular biomarker or imaging technology can assist in predicting or assessing response. Studies directed at defining the pharmacokinetics (PK) of a drug, or its effect on specific target cells (pharmacodynamics, PD), are often included as components of Phase 1 or feasibility trials, but are sometimes executed as stand-alone studies. These types of trials are referred to as "early phase" trials and they have an essential role in the successful development and regulatory approval of novel therapeutics and diagnostics. These trials are challenging to perform and often require personnel with substantial pharmacology and research laboratory experience in addition to the skills of a clinical investigator. The rate at which novel therapeutics can proceed through early phase trials is the gating factor that determines how quickly the larger scale Phase 2 and Phase 3 trials that are required to demonstrate efficacy compared to standard therapy can be initiated. Improving the efficiency of these early phase trials is one of the goals of the FDA's "critical pathway" initiative and is a major focus of the clinical trials program of the Moores Cancer Center. We believe that it is appropriate to commit the resources of the Protocol Specific Research component of the CCSG application to this effort.